Face driver

Abstract

A face driver with a receiving body (1) in which a compression spring (2) is arranged for the indirect or direct support of a support cylinder with a centering point (4), and with a driving disc (7) surrounding the support cylinder and intended for contact with a workpiece, wherein a plurality of support bolts (5) are arranged in an axially movable manner in off-center receptacles aligned parallel to the center axis in a driving head (3) that is non-rotatably coupled to the receiving body (1), wherein each support bolt (5) engages with a centering head (10) in a radial groove (8) formed on the side of the driving disc (7) facing away from the workpiece, characterized in that the support bolts (5) are supported with their end facing away from the driving disc (7) on a compensating disc (6),and that at least three of the support bolts (5) are provided to provide a three-point support and the compensating disc (6) is spherically guided in a bearing on the receiving body (1) in order to align the ends of the support bolts (5) facing the drive disc (7).

Description

[0001] The invention relates to a face driver with a receiving body in which a compression spring is arranged for the indirect or direct support of a support cylinder with a centering point, and with a driving plate surrounding the support cylinder and intended for contact with a workpiece, wherein in a driving head coupled in a rotationally fixed manner to the receiving body, a plurality of support bolts are arranged axially movably in eccentric receptacles aligned parallel to the center axis, wherein the support bolt engages with a centering head in a radial groove which is formed on the side of the driving plate facing away from the workpiece.

[0002] Face drivers are used in conjunction with a tailstock quill to clamp workpieces at their faces when clamping at the sides or peripheral surfaces is not possible, for example, because machining is to take place there. Clamping at the faces means that torque must also be transmitted via the faces of the workpiece, and the forces acting during axial and radial machining must not affect the clamping and position of the workpiece.

[0003] A face driver is described in DE 100 59 116 A1, in which an intermediate disk and a wobble plate are arranged between the receiving body and the workpiece, with the intermediate disk and the wobble plate each being supported by steel rollers that are aligned orthogonally to one another. DE 17 03 830 U discloses a face driver with the features of the preamble of claim 1. GB 725 439 A shows a compensating disk. In DE 195 34 073 A1, a pendulum ring is used to enable the adjustment of the two support bolts for compensation. DE 11 28 255 B discloses a driver tip with a centering tip mounted in the tip housing against yielding pressure and axially movable driver bolts that are supported on a plastic or flowing medium located in a common pressure chamber.

[0004] Furthermore, a face driver from Basile GmbH is known from obvious prior use. This driver uses a wedge lever compensation system that enables drive via four drive pins. The wedge lever body is held in the correct position by two wedge lever pins, which in turn are supported by two wedge lever supports. Two floating plates are located on the wedge lever body, which are held in position by two elastic elements on the wedge lever body. The four drive pins are guided by the drive pin head. The centering point is independent of the drive pin and is tensioned by a disc spring assembly. The drive pins can be exchanged for left- or right-hand rotation.

[0005] The invention is based on the object of designing a face driver of the type mentioned at the outset in such a way that the compensating, backlash-free driving functions in left and right rotation can be integrated into the existing design of conventional face drivers and at the same time the operating and maintenance effort is reduced.

[0006] This object is achieved according to the invention by a face driver according to claim 1. Expedient further developments and advantageous embodiments of the invention are specified in the subclaims.

[0007] The face driver according to the invention is characterized by its very simple design, in which the torque can be transmitted from the receiving body coupled to the lathe's work spindle to the drive plate via the support bolts engaging in the grooves of the drive plate. The axial adjustability of the support bolts enables the drive plate to be driven in an oscillating manner, i.e. the drive plate can adapt to inclined workpiece surfaces without impairing the clamping and torque transmission of the workpiece at its face. On the side facing the workpiece, the drive plate can have serrations, although the invention can also be implemented with any other known variant for the contact between the face of the workpiece and the drive plate.

[0008] The support bolts are supported with their end facing away from the drive plate on a shim. This links the axial adjustability of the support bolts to one another and compensates for the contact of the drive plate against the end face of the workpiece via the support bolts acting on the drive plate. At least three support bolts are provided and the shim is spherically guided on a bearing on the mounting body. This design provides a three-point support in which the ends of the support bolts facing the drive plate are aligned accordingly via the spherical guide of the shim on the mounting body. Alternatively, it is also possible to provide inclined surfaces on the shim that are assigned to the support bolt. These inclined surfaces allow the shim to be radially adjusted to compensate for the contact of the drive plate with a flat surface on the mounting body.The grooves have V-shaped zones for interaction with the associated centering heads, which particularly promotes the support bolts' play-free interaction with the drive plate and, in particular, ensures that switching between clockwise and counterclockwise rotation does not disrupt the oscillating drive. The interaction of the three-point support and the guidance of the support bolts in the V-shaped, prismatic zones of the grooves prevents the drive plate from twisting, regardless of the direction of force and the oscillating function.

[0009] In order to further promote the interaction of the support bolts with the grooves of the drive plate, the centering heads have spherical centering surfaces so that the support bolts can align themselves via the spherical centering surfaces in the V-shaped zones in the grooves and this alignment is maintained regardless of the direction of rotation of the work spindle.

[0010] Within the scope of the invention, it is further provided that the support cylinder extends through a central passage of the compensating disc, i.e. the compensating disc is arranged on the support cylinder and thus essentially performs a pivoting movement without being able to slip radially.

[0011] The invention is explained in more detail below using an embodiment shown in the drawing; in which: Fig. 1 a longitudinal section through a face driver according to the invention, Fig. 2 two perspective views of the drive plate from different views, and Fig. 3 a perspective view of the support bolt.

[0012] In the drawing, Fig.1 shows a longitudinal section of an end face driver according to the invention, which can be coupled to the work spindle of a machine tool by means of its receiving body 1. Arranged in the receiving body 1 is a compression spring 2 for directly or indirectly supporting a support cylinder with a centering point 4, wherein the pressure can be used to adjust the centering force of the centering point 4 and thus define its position during the centering function. The end face driver further comprises a driver plate 7 surrounding the support cylinder and intended for contact with the workpiece, as well as a driver head 3 in which a plurality of support bolts 5 are arranged for axial movement in off-center receptacles aligned parallel to the center axis.The driver head 3 is coupled to the receiving body 1 in a rotationally fixed and axially immovable manner. In the embodiment shown in the drawing, this is achieved by screws that penetrate the driver head 3 and engage in an associated threaded bore in the receiving body 1, which are evenly distributed over the circumference. Each support bolt 5 engages with a centering head 10 having a spherical centering surface in a radial groove 8 of the driver plate 7, which has a V-shaped, prismatic zone 9 for interaction with the associated centering head 10.

[0013] In the embodiment shown in the drawing, the support bolts 5 are supported with their end facing away from the drive plate 7 on a compensating disc 6, which is spherically guided in a bearing on the receiving body 1. The embodiment shown in the drawing comprises three support bolts 5, which ensure three-point support of the drive plate 7. The support cylinder extends through a central passage of the compensating disc 6.

[0014] The face driver according to the invention now enables the drive disk 7, which is toothed on the side facing the workpiece, to be seated on the workpiece, even if its face is oriented obliquely relative to the axis of the work spindle and the face driver. When the workpiece is clamped in cooperation with a tailstock quill, the drive disk 7 leans against the face of the workpiece and, in the process, adjusts the support bolts 5 in the holders in a compensating manner via the compensating disk 6. At the same time, the spherical centering surfaces of the centering heads 10 of the support bolts 5 are pressed into the grooves 8 with the V-shaped zones 9, so that a play-free, pendulum drive of the drive disk 7 is achieved. List of reference symbols 1 receiving body 2 compression springs 3 Driving head 4 Centering point 5 support bolts 6 shim 7 Drive plate 8 grooves 9 Zone 10 Centering head

Claims

[1] Face-side driver with a receiving body (1) in which a compression spring (2) for the indirect or direct support of a support cylinder with a centering point (4) is arranged, and with a driving disc (7) surrounding the support cylinder and intended for contact with a workpiece, wherein in a driving head (3) which is coupled in a rotationally fixed manner to the receiving body (1), a plurality of support bolts (5) are arranged axially movably in eccentric receptacles aligned parallel to the center axis, wherein each support bolt (5) engages with a centering head (10) in a radial groove (8) which is formed on the side of the driving disc (7) facing away from the workpiece, characterized bythat the support bolts (5) are supported with their end facing away from the drive plate (7) on a compensating plate (6), and that at least three of the support bolts (5) are provided to provide a three-point support and the compensating plate (6) is spherically guided in a bearing on the receiving body (1) in order to align the ends of the support bolts (5) facing the drive plate (7). [2] Face carrier according to claim 1, characterized by that the grooves (8) have V-shaped zones (9) for interaction with the associated centering heads (10). [3] Face carrier according to claim 2, characterized by that the centering heads (10) have spherical centering surfaces. [4] Face carrier according to one of claims 1 to 3, characterized by that the support cylinder extends through a central passage of the compensating disc (6).

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